During a recent meeting with Motion System Design representative Melinda Hurley, we discussed with Miriam Metcalfe of Wittenstein Inc., Bartlett, Ill. (rack-and-pinion, mechatronics, and actuator-components manufacturer) the relative merits of technical mobile apps — those smartphone and tablet tools designed to assist and entertain engineers on the move. Part of the charm of apps, of course, is their efficient delivery of information and amusement in a compact, instant format.

Make no mistake: The most useful — and breathtaking — apps allow interaction with the real world that can't be accomplished with a mere Internet connection and web browser. General-audience case in point: Crème de la crème Star Walk leverages a mobile device's GPS and accelerometers to map the night sky as the user points it towards the heavens — a tool infinitely more engaging than a mere online plot of constellations. Or consider the popular and practical iHandy Level, a digital replacement of the classic builder's standby: It's incredibly useful when hanging a picture and the real level is hiding in the garage. No doubt, some of you already have Shazam to identify songs on the fly, after just a quick listen; several birdcall apps serve the same function for those beguiled by avian songwriters. Other addictive apps include Urban Spoon for location-based restaurant picking … Skype for international calls on the cheap … MyRadar for weather … Dropbox for cloud computing … Amazon barcode scan for quick price comparisons … and the list goes on (and on).

Do you know of any engineering apps that rise to this level of usefulness? How do burgeoning apps for design and analysis stack up? I propose that the most essential are those that leverage a system's mechatronic and networking capabilities to enable remote monitoring and smartphone-based diagnosis — or the sensing capabilities of the smartphone itself. For a sampling of other app reviews by our esteemed colleague Leslie Gordon on Machine Design, visit machinedesign.com and search Gordon+iPhone: Modeling and CAD programs top some of her lists. Other apps that you may find intriguing are Civil Calcs (particularly if statics analysis is part of your job), Multi Seismometer, NOVA Brain Pro and (one of my favorites) Notify.

What must an engineering app offer in order to inspire your download? I personally welcome your emails and commentary on this. Our publishing group is now in the business of app development — and we recognize that these tools are of little value if they're not advantageous to you.